Standardised B-scan and A-scan echographic evaluation of spontaneous anterior uveal melanomas in the dog.

In humans, A-scan echographic characteristics of choroidal and ciliary body malignant melanomas permit the prediction of histopathological findings in >95% of cases. The aim of this study was to determine the echographic characteristics, in A-mode and B-mode, of 16 spontaneous anterior uveal melanomas in the dog using a 10 MHz sector transducer. The acoustic hallmark of the tumours was their low to medium reflectivity, internal vascularity and hard consistency. All had an irregular shape, with no acoustic shadowing and the regular lesional spikes. In our experience, the most important sonographic differential diagnoses are ciliary body adenocarcinoma and chronic inflammatory lesions. We believe that standardised A-scan echography can be used in the evaluation and diagnosis of a very high percentage of anterior uveal melanomas.